#include <stdio.h>
int multiple_by_add(int a, int b)
{
	int flag = 1, result = 0;
	while(a) {
		if (flag & a) 
			result += b;
		b += b;
		a >>= 1;
	}
	return result;
}
void main (void)
{
	char a = 3, b =64;
	printf("a*b %d\n", multiple_by_add(a, b));
}
